Chair Leg Rest Assembly

ABSTRACT

A chair leg rest assembly includes a supporting arm pivotally coupled to a chair seat, and a leg rest frame that can slide along and be selectively positioned on the supporting arm for providing a support plane. An upper end of the supporting arm is flanked by two pivot holders that are fixed to the seat. One of the pivot holders has a pawl portion to be engaged with a pawl portion of a pawl core that is received in the upper end of the supporting arm and resiliently pushed outward. As the supporting arm pivots against and is positioned with respect to the pivot holders, the leg rest frame can be retracted under or expanded before the seat. Then the leg rest frame can slide outward and to support a user&#39;s stretched legs on the support plane thereof. The leg rest assembly is thereby easy to operate.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to leg rests of chairs, and more particularly, to a leg rest assembly attached to a lower front edge of a chair seat, wherein the leg rest assembly can pivot and be positioned with respect to the seat, and its leg rest frame can be pushed outward so that a user can have his/her legs supporter by the leg rest assembly comfortably.

2. Background of the Invention

Conventionally, an office chair has a backrest for supporting a chair user's back and armrests for supporting the user's arms, but has no means to provide the user's legs with comfort. On the other hand, leg rests have long been a part of other chairs such as massage chairs, lounge chairs and sofas. For equipping an office chair with the function of supporting legs, Taiwan Utility Patent No. M399663 titled “Folding Leg rest for Chair” (China Patent Application No. CN201020544789 has been filed for the same invention) provides a structure mainly composed of two rotational arms and a carrying plane articulated between the two rotational arms. The two rotational arms are further articulated to a chair's seat. Thereby, a user can put his/her feet on the carrying plane, so as to facilitate blood circulation and relax feet. This design is adaptive to users of all heights, leg types and leg lengths.

However, in the foregoing device, the carrying plane can be positioned and support the user's legs only when the two rotational arms pivot outward and the carrying plane also pivots outward. In the event that the user needs the carrying plane to be posed inclined, the foregoing device is incompetent. Furthermore, since the carrying plane is articulated between the terminals of the two rotational arms, and the distance between the rotational arms is approximately equal to the width of the seat, when a user intends to use the carrying plane, he/she has to first open his/her legs or the two rotational arms and the carrying plane cannot expand. Although expanding the carrying plane is not a difficult operation, retracting it is another story. For retracting the carrying plane, the user has to first move his/her legs from the leg rest to the ground, and then stretch his/her hands to pivot the carrying plane inward. However, at this time, the expanded carrying plane is relatively distant from the user, it is inconvenient an difficult for the user to properly exert force and pivot the carrying plane inward with his/her hands. The user may thus try to draw the carrying plane back with his/her insteps, but there is no corresponding design or mechanism in the existing device to answer such operation. Therefore, the operation is inconvenient.

SUMMARY OF THE INVENTION

For remedying the inconvenience in operation of the existing leg rest assembly, the present invention provides a leg rest assembly having a supporting arm pivotally coupled to a front lower end of a chair seat and a leg rest frame that is mounted around the supporting arm and has a support plane, so that the leg rest frame can slide along and selectively positioned on the supporting arm, whereby the supporting arm is easy to pivot and position while the leg rest frame is easy to shift and position.

To this end, according to the present invention, the leg rest assembly comprises a positioning base unit, a supporting arm pivotally coupled to the positioning base unit, and a leg rest frame mounted on the supporting arm, therein: the positioning base unit having a first pivot holder and a second pivot holder flanking a pivot portion formed atop the supporting arm, a bolt passing through the first pivot holder, the pivot portion, an axially movable pawl core and the second pivot holder before engaged, wherein the pawl core is received in the pivot portion and resiliently pushed outward, and has an outer side thereof formed with a pawl portion while the second pivot holder is provide with another pawl portion that is configured to engage with the pawl portion of the pawl core, and wherein the supporting arm has at least two positioning holes provide at two ends of an inner side thereof; the leg rest frame having a sliding channel for the supporting arm to be inserted therein, and a positioning member and a spring being sandwiched between the sliding channel and the supporting arm so that the positioning member is resiliently pressed into and positioned by one corresponding said positioning hole.

In the foregoing scheme, the two pivot holders are attached to two laterals of a fastening seat.

In the foregoing scheme, a push button provided at an outer side of the second pivot holder is peripherally formed with a plurality of pins and resiliently pushed outward, such that the pins pass through the second pivot holder and contact the pawl core, whereby pins abut against the pawl core.

In the foregoing scheme, the first pivot holder has a retaining recess for providing rotational limits in both directions, and the pivot portion of the supporting arm has an abutting portion so that the abutting portion is movably received in the retaining recess.

Thereby, in the disclosed leg rest assembly attached to the front lower end of the office chair seat, the supporting arm can pivot to make the leg rest frame retracted under the seat or expanded and positioned in front of the seat for supporting a user's lift and stretched legs. The user can readily slide the leg rest frame inward or outward with a pushing motion or drawing motion made by his/her feet. Thus, the convenient operation makes the disclosed leg rest assembly more practicable.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an office chair equipped with a leg rest assembly of the present invention.

FIG. 2 is a front exploded view of the leg rest assembly of the present invention.

FIG. 3 is a back exploded view of the leg rest assembly of the present invention.

FIG. 4 is a cross-sectional view of a positioning base unit in the leg rest assembly of the present invention.

FIG. 5 is a cross-sectional view of a supporting arm and a leg rest frame in the leg rest assembly of the present invention.

FIG. 6 is a lateral view of the office chair equipped with the leg rest assembly showing the leg rest assembly retracted under the chair seat.

FIG. 7 is a lateral view of the office chair equipped with the leg rest assembly showing the leg rest assembly expanded.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIG. 1, according to the present invention, a leg rest assembly S is attached to a lower front edge of a seat of an office chair and primarily comprises a positioning base unit 1 fixed to the seat, a supporting arm 2 pivotally coupled to the positioning base unit 1, and a leg rest frame 3 that is slidably mounted on the supporting arm 2 and has a support plane. As shown in FIG. 2, FIG. 3 and FIG. 4, the positioning base unit 1 is composed of a fastening seat 10 fixed to the seat, and a pair of pivot holders 11 a and 11 b attached to two laterals of the fastening seat 10. The supporting arm 2 is atop provided with a pivot portion 20 that is pivotally connected to and between the two pivot holders 11 a and 11 b. The first pivot holder 11 b, or the right pivot holder in the depicted embodiment, has a column 110 raised from its lateral. The column 110 has a retaining recess 111 for providing rotational limits in both directions. Correspondingly, the pivot portion 20 of the supporting arm 2 has its lateral formed with a socket 24 for receiving the column 110, and there is an abutting portion 23 provided in the socket 24 so that the abutting portion 23 is movably received in the retaining recess 111 to limit a pivot angle of the supporting arm 2 against the pivot holders 11 a and 11 b within a predetermined range. In addition, a bolt 17 is provided to pass through the pivot holders 11 b, the pivot portion 20, a spring 12 and a pawl core 13 before passing through the second or left pivot holder 11 a and getting fastened with a nut 14. The pawl core 13 has one end thereof formed with a polygonal anti-rotation portion 131 that is received in a matching polygonal depressed receiving portion 21 formed correspondingly on the pivot portion 20, so that the spring 12 is received within the depressed receiving portion 21 and resiliently pushes the pawl core 13 outward. An opposite end of the pawl core 13 is formed with a pawl portion 132 for engaging with a pawl portion 113 correspondingly provided on the left pivot holder 11 a. Moreover, a push button 15 is provided at an outer side of the pivot holder 11 a. The push button 15 is peripherally formed with a plurality of pins 151. The pins 151 are received in grooves 112 formed in the pivot holder 11 a such that each said pin 151 has its terminal abutting against the pawl core 13. Another spring 16 is arranged between the push button 15 and the pivot holder 11 a, so that the spring 16 resiliently props the push button 15 outward. When the push button 15 is pushed inward, the pins 151 push the pawl core 13 to make the pawl portion 132 of the pawl core 13 move inward and disengage from the pawl portion 113 of the pivot holder 11 a, so that the supporting arm 2 is allowed to pivot. When the push button 15 is released, the pawl core 13 and therefore the push button 15 are repositioned due to the resilience of the springs 12 and 16. This also makes the pawl portions 132 and 113 of the pawl core 13 and the pivot holder 11 a reengage with each other, allowing the supporting arm 2 to be held at a desire pivot angle.

Referring additionally to FIG. 5, the supporting arm 2 has an inner cavity formed with a plurality of positioning holes 22. The supporting arm 2 is inserted into a sliding channel 31 formed on the leg rest frame 3. A cover 32 is then such assembled to a receiving portion at an upper end of the sliding channel 31 that a positioning member 33 and a spring 34 pushing the positioning member 33 sandwiched between the cover 32 and the supporting arm 2. Thereby, the positioning member 33 is resiliently pressed into and engaged with the corresponding positioning hole 22. In this manner, the leg rest frame 3 is allowed to slid along the supporting arm 2 and selectively positioned by any of the positioning holes 22 on the supporting arm 2.

Therefore, as shown in FIG. 6, when not in use, the leg rest assembly S pivots downward (retracts) and is positioned under the seat. When the leg rest assembly S is to be used, as shown in FIG. 7, the assembly of the supporting arm 2 and the leg rest frame 3 pivots upward (expands) from the position under the seat to a position in front of the seat and then gets positioned. Afterward, the leg rest frame 3 slides outward along the supporting arm 2 and then positioned, so that the leg rest frame 3 is ready to support a user's stretched legs. As described, the leg rest assembly S is easy to operate, and the user can readily slide the leg rest frame 3 inward or outward with a pushing motion or drawing motion made by his/her feet, thereby achieving more convenient operation. 

1. A chair leg rest assembly, comprising a positioning base unit, a supporting arm pivotally coupled to the positioning base unit, and a leg rest frame slidably mounted on the supporting arm, therein: the positioning base unit having a first pivot holder and a second pivot holder flanking a pivot portion formed atop the supporting arm, and a bolt passing through the first pivot holder, the pivot portion, an axially movable pawl core and the second pivot holder before engaged, wherein the pawl core is received in the pivot portion and resiliently pushed outward, and has an outer side thereof formed with a pawl portion while the second pivot holder is provide with another pawl portion that is configured to engage with the pawl portion of the pawl core, and wherein the supporting arm has at least two positioning holes provide at two ends of an inner side thereof; the leg rest frame having a sliding channel for the supporting arm to be inserted therein, and a positioning member and a spring being sandwiched between the sliding channel and the supporting arm so that the positioning member is resiliently pressed into and positioned by one corresponding said positioning hole.
 2. The chair leg rest assembly of claim 1, wherein the two pivot holders are attached to two laterals of a fastening seat.
 3. The chair leg rest assembly of claim 1, wherein a push button provided at an outer side of the second pivot holder is peripherally formed with a plurality of pins and resiliently pushed outward, such that the pins pass through the second pivot holder and abut against the pawl core, whereby pushing the push button makes the engaged pawl portions of the second pivot holder and the pawl core disengage from each other.
 4. The chair leg rest assembly of claim 1, wherein the first pivot holder has a retaining recess for providing rotational limits in both directions, and the pivot portion of the supporting arm has an abutting portion so that the abutting portion is movably received in the retaining recess. 